Every time I fuel up I get fault codes - ideas?

[ant1]

Couple of months ago I was having issues with my car throwing 2x codes saying both banks running rich. This was caused by me running the tank quite low due to inaccurate gauge.

After a 500 quid bill from MRC they said the 2x rubber fuel lines in the bay where breaking down causing the fuel reg to block up with rubber as the fuel return pipe going back to the tank. This would cause higher fuel pressure in the rail hence running rich

So they replaced the pipes, changed the fuel filter and everything was ok for 3 tanks until it started again.

So every time I go down the last 1/4 in the tank and fuel up my car throws these codes a few times. Once I have cleared them that's it until the next tank.

Any ideas chaps because this is starting to piss me off.

I have 2x thoughts. Swarf in tank getting drawn up when tank low? Surely filter would pick this up?

Or there is a fuel pressure problem?

I have a whole week off next week so would like to get this sorted

[chunky79]

I know the b5 lads were having lots of issues a few years ago with Tesco petrol stripping the fuel lines.
I would have thought if you had debris in the tank you would get fuel starvation from the pick up getting blocked. I wonder if your breather is playing up causing the tank to become pressurised,? When you remove your fuel cap does it hiss?

[ant1]

Will check that tomorrow. Do you mean the lines from the tank moving upto the engine bay? Not used tesco fuel for a while now but I was using it.

[chunky79]

Yes mate. If there were debris in the tank the pick up pipe would get them due to the suction from the pumps.

[ant1]

Ok cheers, no hissing this morning. If the pumps are picking up surely the filter would catch the debris? Do the pumps have filters like the walbro pumps?

[chunky79]

No idea about the filter in the pumps mate. What i'm trying to say is, if you have swarf/debris in the tank then i would axpect fuel starvation issues due to the feed to the engine being restricted.

[Cbrt]

Do you overfill I.e keep the fuel filling right upto the top?

I've experienced problems with that before forcing it full

[ant1]

I fill until it clicks, what I will say is that there is not a problem once I have covered 40 miles on a new tank.

Will whip the fuel pressure region off tomorrow and see if it's full of debris.

[RS6JJL]

remember reading on here somewhere if you fill to the top it can trigger a fault code

[chunky79]

Must be random cars then cause I don't get the issue.